题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=3536
题目大意:给一面矩形墙染色(染色也是矩形状),求有多少染色块被其他染色快完全覆盖.
题目思路:
(1)离散后暴力直接搞.
(2)矩形树(四分线段树),但是居然没有比暴力快= =!,不过自己测了一组染色1000次的数据,明显矩形树比较快.
代码:
(1)
#include <stdlib.h> #include <string.h> #include <stdio.h> #include <ctype.h> #include <math.h> #include <time.h> #include <stack> #include <queue> #include <map> #include <set> #include <vector> #include <string> #include <iostream> #include <algorithm> using namespace std; #define ull unsigned __int64 #define ll __int64 //#define ull unsigned long long //#define ll long long #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define middle (l+r)>>1 #define MOD 1000000007 #define esp (1e-4) const int INF=0x3F3F3F3F; const double DINF=10001.00; //const double pi=acos(-1.0); const int N=1010; int n,m; int mtx[N<<1][N<<1],X[N<<1],Y[N<<1],xc,yc,cnt,vis[N]; struct node{ int x1,y1,x2,y2; void write(){ scanf("%d%d%d%d",&x1,&y1,&x2,&y2); if(x1>x2) swap(x1,x2); if(y1>y2) swap(y1,y2); } }a[N]; int bs(int key,int size,int A[]){ int l=0,r=size-1,mid; while(l<=r){ mid=middle; if(key>A[mid]) l=mid+1; else if(key<A[mid]) r=mid-1; else return mid; }return -1; } int main(){ //freopen("1.in","r",stdin); //freopen("1.out","w",stdout); int i,j,k,r,c,x1,y1,x2,y2; //int T,cas=0;scanf("%d",&T);for(cas=1;cas<=T;cas++) while(~scanf("%d%d%d",&r,&c,&n)){ for(i=m=0;i<n;i++){ a[i].write(); X[m]=a[i].x1,Y[m]=a[i].y1,m++; X[m]=a[i].x2,Y[m]=a[i].y2,m++; } sort(X,X+m);sort(Y,Y+m); for(i=xc=1;i<m;i++) if(X[i]!=X[i-1]) X[xc++]=X[i]; for(i=yc=1;i<m;i++) if(Y[i]!=Y[i-1]) Y[yc++]=Y[i]; memset(mtx,0,sizeof(mtx)); for(i=0;i<n;i++){ x1=bs(a[i].x1,xc,X),x2=bs(a[i].x2,xc,X); y1=bs(a[i].y1,yc,Y),y2=bs(a[i].y2,yc,Y); for(j=x1;j<=x2;j++) for(k=y1;k<=y2;k++) mtx[j][k]=i; } memset(vis,0,sizeof(vis)); for(i=cnt=0;i<xc;i++){ for(j=0;j<yc;j++) if(mtx[i][j]){ if(!vis[mtx[i][j]]) cnt++,vis[mtx[i][j]]=1; } } printf("%d\n",n-cnt); } return 0; }
#include <stdlib.h> #include <string.h> #include <stdio.h> #include <ctype.h> #include <math.h> #include <time.h> #include <stack> #include <queue> #include <map> #include <set> #include <vector> #include <string> #include <iostream> #include <algorithm> using namespace std; #define ull unsigned __int64 #define ll __int64 //#define ull unsigned long long //#define ll long long #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define middle (l+r)>>1 #define MOD 1000000007 #define esp (1e-4) const int INF=0x3F3F3F3F; const double DINF=10001.00; //const double pi=acos(-1.0); const int N=1010; int n,m; int X[N<<1],Y[N<<1],xc,yc; int cov[(N*N)<<1],vis[N],cnt; struct node{ int xl,xr,yl,yr; int xmid(){return (xl+xr)>>1;} int ymid(){return (yl+yr)>>1;} }; node New(int xl,int xr,int yl,int yr){ node r; r.xl=xl,r.xr=xr; r.yl=yl,r.yr=yr; return r; } struct rct{ int x1,y1,x2,y2; void write(){ scanf("%d%d%d%d",&x1,&y1,&x2,&y2); if(x1>x2) swap(x1,x2); if(y1>y2) swap(y1,y2); } }a[N]; int bs(int key,int size,int A[]){ int l=0,r=size-1,mid; while(l<=r){ mid=middle; if(key>A[mid]) l=mid+1; else if(key<A[mid]) r=mid-1; else return mid; }return -1; } void PushDown(int rt){ if(cov[rt]!=-1){ cov[(rt<<2)-2]=cov[(rt<<2)-1]=cov[rt]; cov[rt<<2]=cov[rt<<2|1]=cov[rt]; cov[rt]=-1; } } void Update(node p,int rt,node P,int c){ if((P.xl<=p.xl&&p.xr<=P.xr) && (P.yl<=p.yl&&p.yr<=P.yr)){ cov[rt]=c; return; } PushDown(rt); int xmid=p.xmid(),ymid=p.ymid(); if(P.xl<=xmid){ if(P.yl<=ymid) Update(New(p.xl,xmid,p.yl,ymid),(rt<<2)-2,P,c); if(ymid<P.yr) Update(New(p.xl,xmid,ymid+1,p.yr),(rt<<2)-1,P,c); } if(xmid<P.xr){ if(P.yl<=ymid) Update(New(xmid+1,p.xr,p.yl,ymid),rt<<2,P,c); if(ymid<P.yr) Update(New(xmid+1,p.xr,ymid+1,p.yr),rt<<2|1,P,c); } } void Query(node p,int rt){ if(cov[rt]!=-1){ if(!vis[cov[rt]]) vis[cov[rt]]=1,cnt++; return; } if(p.xl==p.xr && p.yl==p.yr) return; PushDown(rt); int xmid=p.xmid(),ymid=p.ymid(); Query(New(p.xl,xmid,p.yl,ymid),(rt<<2)-2); if(ymid<p.yr) Query(New(p.xl,xmid,ymid+1,p.yr),(rt<<2)-1); if(xmid<p.xr){ Query(New(xmid+1,p.xr,p.yl,ymid),rt<<2); if(ymid<p.yr) Query(New(xmid+1,p.xr,ymid+1,p.yr),rt<<2|1); } } int main(){ //freopen("1.in","r",stdin); //freopen("1.out","w",stdout); int i,j,k,r,c,x1,y1,x2,y2; //int T,cas=0;scanf("%d",&T);for(cas=1;cas<=T;cas++) while(~scanf("%d%d%d",&r,&c,&n)){ for(i=m=0;i<n;i++){ a[i].write(); X[m]=a[i].x1,Y[m]=a[i].y1,m++; X[m]=a[i].x2,Y[m]=a[i].y2,m++; } sort(X,X+m);sort(Y,Y+m); for(i=xc=1;i<m;i++) if(X[i]!=X[i-1]) X[xc++]=X[i]; for(i=yc=1;i<m;i++) if(Y[i]!=Y[i-1]) Y[yc++]=Y[i]; memset(cov,-1,sizeof(cov)); for(i=0;i<n;i++){ x1=bs(a[i].x1,xc,X),x2=bs(a[i].x2,xc,X); y1=bs(a[i].y1,yc,Y),y2=bs(a[i].y2,yc,Y); Update(New(0,xc-1,0,yc-1),1,New(x1,x2,y1,y2),i); } memset(vis,0,sizeof(vis));cnt=0; Query(New(0,xc-1,0,yc-1),1); printf("%d\n",n-cnt); } return 0; }